Spring assembly for upholstery



July 21, 1936.

Flgll.

A. N. LISSON SPRING ASSEMBLY FOR UPHOLSTERY Filed April 13, 1954lnvenTor. Abraham N. Lisson b MMkW AiTys.

Patented July 21, 1936 UNITED STATES SPRING ASSEMBLY FOR UPI-IOLSTERYAbraham N. Lisson, Lynn, Mass., assignor to Lisson-Melen Company, Lynn,Mass., a corporation of Massachusetts Application April 13, 1934, SerialNo. 720,411

1 Claim.

This invention relates to a spring assembly for upholstery purposes suchas is employed in the seat, back, and side cushioning of furniture,automobiles, railway cars, in mattresses and in other articles.

The object of the invention is to provide an efficient, durable strong,an economical unit and one which may be readily and economicallymanufactured.

The object of the invention is further to provide such a spring assemblycomposed of expansion helical wire springs with the expansion of thesprings limited and with the springs held in definite spaced relation.

.The object of the invention is further to provide a' construction inwhich the springs are arranged in separated rows and in which thesprings in each row are prevented from contacting or rubbing againsteach other by strips of fabric which at the same time'act to limit theexpansion of the springs.

The object of the invention is further to provide such a spring assemblyin which the fabric strips are of a novel construction and are combinedin a novel way with the springs so as to produce a strong, durable andefficient arrangement at low cost.

These and other objects and-features 'of the invention will appear morefully from the accompanying description and drawing and will beparticularly pointed out in the claim.

The construction shown in the drawing as a simple and preferredembodiment of the invention is a spring assembly designed for a seatcushion and the applicability of the invention to other purposes will beapparent therefrom. Only a complete spring assembly is shown and it willbe understood that the assembly is to be covered or encased withsuitable fabric and be padded or otherwise treated in any usual ordesiredlway. The assembly unit is shown as composed of a plurality ofsimilar expansion helical wire springs of cylindrical shape. Thecylindrical shape is preferred because such springs give greattransverse rigidity to the unit and contract and e"- pand with greatuniformity, especially at the margins of the unit. But it will beunderstood that the hour-glass or other type of expansion helical wiresprings may be employed if desired.

In the drawing:

Fig. 1 is a plan view of the spring assembly unit.

Fig. 2 is a view in vertical cross section taken on the line 2-2 of Fig.1.

Fig. 3 is a detail in perspective of one corner of the unit.

The springs are all preferably of the same size and type, each being anexpansion spring and each in the form of a helical wire, the dimen- 6sions of the springs depending upon the desired use of the assembly.

These springs are arranged in rows with the rows spaced apart from eachother. In the particular construction illustrated, as shown in Fig. 10

1, there are four such rows each containing five springs.

In each row the two springs of each pair of adjacent springs, forexample, the pair of springs l-Z, the pair 2'3, the pair 3 l, and thepair t5, have their expansion limited and are maintained out of contactby a single endless fabric strip. In each case this fabric strip may bemade of any suitable fabric, such, for example, as bur- I lap, and ispreferably brought into endless form by sewing together the ends of astraight strip of the fabric. These endless strips of fabric are of awidth to give the desired strength and equal to a substantial segment ofthe springs. The length of the endless strip doubled is made equal tothe .desired depth or thickness of the spring assembly unit and issubstantially less than the height of the springs when fully expanded.Consequently in the completed assembly the springs never stand at theirfree height but are always somewhat contracted. This gives a highlydesirable even yielding quality to the entire unit.

Since the construction and arrangement of the separating and expansionlimiting feature is the same for each pair of adjacent springs, it willbe sufiicient to describe that for the pair of adjacent springs l and Z.The fabric strip 6 is arrange to encircle the coils. of. one of thesprings, in this case the spring i, throughout the segment of the springadjacent-the other spring 2. With the endless strip formed from astraight piece of fabric as illustrated, this is very readily done byproviding a strip of the required length, compressing the spring,inserting the strip' in the spring and stitching the ends I together at8. The uppermost coil of the spring I which is encircled by the fabricstrip, the uppermost coil of the adjacent spring 2 and both plies of thefabric strip are then secured together. The same thing is also done atthe bottom of the unit, that is, the lowermost coil of the spring I, thelowermost -coil of the spring 2, and the two plies of the fabric stripare all secured together. Thus it'will be seen that the expansion ofboth springs is limited by theendess fabric strip and that the two adja-55 cent springs i and 2 are separated by the fabric. Furthermore, sinceboth plies of the endless strip are secured at the top and bottom to thecoils of the springs, even if one play should become worn or broken, theother ply will still function to limit the expansion of the springs sothat the thickness of. the assembly will remain uniform throughout.There is little chance of the unstitched ply breaking and this ply isthe one which separates the adjacent springs.

The means employed for securing together the coils of the two adjacentsprings and the two plies of the fabric strip is shown in Figs. 1, 2,and 3, wherein the rows of springs are held in the desired spacedrelation by a plurality of wire helices 9 which extend transversely ofthe rows of springs both at the top and at the bottom of the assembly.One of these wire helices passes between each pair of adjacent springsin each row. In this construction each helix 8 at the top has its coilsinterlaced with the topmost coils of the ad- :Iacent springs, as, forexample, the topmost coils of the springs I and 2, and also isinterlaced with both plies of the fabric strip passing around thetopmost coil of its spring. This may be done by screwing the helix intoplace. .With this construction it will be seen that the wire helices! atthe bottom are interlaced in the same manner and that in this case eachwire helix 9 acts not only as a means for separating the rows ofsprings, but also as a means for securing together the two plies of thefabric strip and the coils of adjacent springs as hereinbefore setforth.

Preferably the spring assembly unit is provided at the top and bottomperipheries with a border wire giving a sharply defined peripheral edgeto the assembly and serving further to distribute pressure on theassembly among the springs. This border wire may be of any desiredconstruction. In the form illustrated one border wire is secured to theuppermost coils and another to the lowermost coils of the springs and isshown at the ends in the form of straight sections l2 and II secured tothe spring coils by metal clips I4, and atthe sides in the form of wirehelices l5 interlaced with the coils of the springs.

It is also desirable that the segments ofthe prings exposed at the endsof the several rows shall have their expansion limited and for thatPurpose the exterior segment of each such end spring is shown asprovided with an endless fabric strip it of the same construction asalready described. Preferably also both plies of these endless fabricstrips at the exterior of the end coils of the rows, together with thecoil of the spring encircled thereby are secured to the border wire atthe top and at the'bottom and, in the illustrated case, this is done bymeans of the clips II which not only clamp the border wire to the springbut also engage and clamp the endless fabric strip where it encirclesthe coil of the The spring assembly may be, and preferably is,reinforced by additional wire struts extending at right angles to thestruts. such as 9 or it. In a spring assembly unit of the size employedin cushions, two such additional wire struts will usu- 5 ally be foundsuflicientand this is the construction shown in the drawing wherein suchstruts shown as wire helices I! are employed, one at the top and one atthe bottom of the unit. These struts pass approximately centrally of theunit. 10 One of these struts I1 is threaded, through the topmost coilsof one row of springs, also through the helices 9, and is anchored atits ends to the end springs. The other is connected in the same wayat'the bottom of a row of springs. These 16 additional struts areadvantageous as they hold the assembly in position when itis forcedafter padding into its cover by a machine such as commonly employed.These struts also act to prevent a spring from bulging out in theassembly as if by chance both plies of a fabric strip should becomebroken.

The construction of this-invention enables the size of spring assemblyunits to be standardized. The rows of springs preferably extendlongitudi- 25 nally of the unit and consequently if springsofsubstantially three inches in diameter are employed, the unit may bemade of any length in multiples of three inches and this covers theusualrange of lengths. The rows of springs may be $0 spaced apart to vary thewidth as desired.

While the border wire has been shown as extending entirely around theperiphery at the top and the bottom, it will be understood that all orany portion of the border wire may be omitted, 35 depending upon the useto which the spring-assembly unitis to be put.

Having thus described the invention, what is elaimedasnew, and desiredtobesecuredbylletters Patent, is: v 40 A spring assembly for upholsterycomprising a plurality of rows of adjacent expansion helical wiresprings, an endless fabric strip for each pair of adjacent springs ineach row, the said strip I in each case'encircling a narrow segment onlyof 45 the coils of one of the said springs adjacent a bare segment ofthe coils of the other spring, the springs in said rowspositioned'withb'are segments of the springs in each row opposite bare segments of thesprings in each'adiacent row, a Q plurality of wire helices extendingtransversely of the rows of springs at the top and at the bottom of theassembly, each wire helix having coilsinterlocking with the end coils ofadjacent springs in each rowand with both pliesof the nuns strips wherethey pass around the end coils and acting both to. secure together theend coils of thesaid adjacent springs and said piles of the fabric stripandto maintain the rows of springs spaced fromeach other.

